1. Field of the Invention
My invention relates to a method of manufacture of a raw material and the process which utilizes it for increasing the percentage of mammalian offspring of either sex, and more particularly to immunological method of increasing the percentage of mammalian offspring of either sex.
2. Description of the Prior Art
Mechanical methods increasing the percentage of mammalian offspring of either sex by providing seminal fluids containing a surplus of either male-determining spermatozoa or female-determining spermatozoa with the aid of the difference in density between male-determining spermatozoa and female-determining spermatozoa are taught in the prior art, e.g., in abandoned U.S. patent application Ser. No. 443,473, in U.S. patent application Ser. No. 814,906, and in a paper by E. Schilling, "Separation of Bull Sperm by Sedimentation and Centrifugation and the Sex of the Born Cows," Zeitschrift fur Saugertierkunde, Volume 31, No. 4, pages 314-323 (1960). Such methods are known, however, to be characterized by reduced sperm survivability, and by reduced viability of the surviving sperm.
The speculation that immunological means can be used to increase the percentage of mammalian offspring of either sex is discussed in a paper entitled "Sex Ratio In Progeny of Mice Inseminated with Sperm Treated with H-Y Antiserum" by Bennett and Boyse, Nature, Volume 246, Nov. 30, 1973, pages 308 and 309.
An immunological method of increasing the percentage of mammalian offspring of either sex is disclosed in U.S. Pat. No. 3,687,806, issued to Gustaaf J. van den Boevenkamp on Aug. 29, 1972. The method of this patent required as a starting material a sperm fraction containing a surplus of either male-determining spermatozoa or female-determining spermatozoa isolated in accordance with the aforementioned abandoned application Ser. No. 443,473, the other above-mentioned application Ser. No. 814,906, or the aforementioned Schilling article, or closely related mechanical methods. Thus, the method of the aforementioned U.S. Pat. No. 3,687,806 necessarily suffers to a greater or lesser degree from the disadvantages of said mechanical methods, i.e., reduced sperm survival and reduced viability of the surviving sperm.
Electrophoresis and other processes are known to the art for sperm separation as well, and those all have their respective shortcomings.